Little is known about the relation of cigarette smoking and early retirement due to permanent disability. We conducted a cohort study among 4796 construction workers aged 40 to 59 who underwent occupational health examinations in 1986-1988 in occupational health centers located in the southern region of Germany. They were followed up with respect to working status until July 1994. The effect of smoking on early retirement due to permanent disability was assessed using the Cox proportional hazard model. Overall, smoking prevalence at baseline was 52%. The relative rate (RR) for permanent disability was 1.3 (95% CI 1.0-1.8) for all current smokers, compared with never-smokers. A positive dose-response relationship between smoking and the rate of early retirement due to permanent disability was found after adjustment for covariates. RR ranged from 1.3 in persons who reported smoking 1-19 cigarettes a day to 1.6 in persons who reported smoking > or = 30 cigarettes a day (P value for trend = 0.02). These findings underline the need for comprehensive efforts at the workplace to reduce smoking and its negative consequences for the individual, as well as to limit the associated social burden for society.